Lately I've been making the "miracle mac and cheese" with skim or 1% milk, then instead of adding more milk in the end, add the cauliflower puree instead. It has no butter or flour, but it comes out super creamy.

That sounds like a great method. I wonder though if the calories might be skewed a bit since the starch from the pasta that normally gets tossed remains in the dish. Maybe not all that much but maybe someone has an idea? I hate to fool myself about calories counts.